This invention relates to the improvement of a video data recording medium on which digital data such as compressed video data, sub-video data and audio data are recorded, for example. Further, this invention relates to the improvement of a video data recording apparatus for recording video data on the video data recording medium. This invention relates to the improvement of a video data playback apparatus for playing back video data from the video data recording medium. This invention makes it possible to easily effect the simple editing operation for video data recorded or played back.
As is well known in the art, recently, it becomes possible to record video data in a compressed form as well as audio data on an optical disk having the same diameter of 12 cm as an audio CD (Compact Disk), for example. As this type of optical disk, for example, a CD-ROM (Read Only Memory) is popularly used in a wide range of field from the education field to information field.
Further, recently, a DVD-ROM or the like which is an optical disk having the same diameter as the CD and on which main video data of an amount corresponding to an approximately 2-hour movie, 8 types of audio data items and sub-video data representing 32 types of captions are recorded is developed. At present, a DVD standard using the MPEG (Moving Picture Image Coding Experts Group) 2 compression system based on the international standard for video data and using the AC-3 compression system for audio data is proposed.
According to the DVD standard, MPEG2 is used for the video compression system according to the MPEG2 system layer, the AC-3 system and MPEG system are supported as the audio compression system, and sub-video data obtained by subjecting bit map data to the run-length compression as the caption and control data (navigation pack) for special playback such as playback at the time of quick feeding and quick returning are additionally provided.
Further, in the DVD standard, ISO (International Organization for Standardization) 9660 and micro UDF (Universal Disk Format) are supported so that data can be read by use of a personal computer and the like, for example.
At present, not only the playback only optical disk such as the DVD-ROM described above but also an optical disk such as a DVD-RAM (Random Access Memory), for example, in which data can be programmed or rewritten is developed and an apparatus for recording/playing back data on or from the optical disk is actively developed.
When video data recorded on or played back from the DVD-RAM is edited according to the DVD standard, it is necessary to effect the editing operation using the authoring system as in the conventional DVD-ROM. For this reason, there occurs a problem that it takes a long time and much labor for the user and the financial burden for preparing a device for the authoring system is imposed on the user.
This invention has been made in view of the above problem and an object of this invention is to provide a video data recording medium, video data recording apparatus and video data playback apparatus in which video data recorded or played back can be easily subjected to the simple editing operation.
A video data recording medium according to this invention comprises a first area in which video data divided into a plurality of unit data items is recorded; a second area in which attribute information for specifying the playback order of the plurality of unit data items recorded in the first area is recorded; and a third area in which first control information for specifying whether data can be played back or not for each of the plurality of unit data items is recorded.
A video data recording apparatus according to this invention comprises recording means for recording video data divided into a plurality of unit data items, attribute information for specifying the playback order of the plurality of unit data items and first control information for specifying whether data can be played back or not for each of the plurality of unit data items on a recording medium.
A video data playback apparatus according to this invention comprises playback means for playing back a recording medium on which video data divided into a plurality of unit data items, attribute information for specifying the playback order of the plurality of unit data items and first control information for specifying whether data can be played back or not for each of the plurality of unit data items are recorded.
Further, the playback means effects the control operation so as not to play back the unit data item which is specified to be inhibited from being played back by the first control information when the plurality of unit data items are played back based on the playback order specified by the attribute information.
With the above construction, since the first control information for specifying whether data can be played back or not for each of the plurality of unit data items is recorded on the recording medium, the simple editing operation for playing back data while skipping unnecessary data portion at the time of playback or restoring the unnecessary data portion can be easily effected without using the authoring system as in the conventional case.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.